1. Technical Field
The present invention relates to the detection and evaluation of ground glass nodules (GGNs) in medical images, and more particularly, to a system and method for detecting solid components of GGNs in pulmonary computed tomography (CT) images.
2. Discussion of the Related Art
With the widespread availability of multi-slice computed tomography (CT) scanners for lung cancer screening and the ever-improving resolution offered by these scanners, an increasing number of small pulmonary nodules are being detected at their early stages for cancer diagnosis.
Lung nodules can be classified into solid nodules and ground glass nodules (GGNs). GGNs can be further grouped into pure GGNs that contain only non-solid (e.g., low-density) elements and mixed GGNs that contain both solid and non-solid components. Solid nodules, pure GGNs and mixed GGNs have different appearances in pulmonary CT images as shown in FIG. 1.
In Feng Li, Shusuke Sone, Hiroyuki Abe, Heber MacMahon and Kunio Doi, “Malignant versus Benign Nodules at CT Screening for Lung Cancer: Comparison of Thin Section CT Findings”, Radiology 2004 233: 793-798, it was shown that GGNs are more likely to be associated with malignancy than solid nodules. The ratio of a solid component to an entire GGN is an important indicator for nodule characterization.
Accordingly, there is a need for a solid component detection method that is capable of providing fast and consistent measures for cancer diagnosis and treatment.